1. Field
The present invention relates to a synchronous DC-DC converter, and more particularly to a synchronous DC-DC converter which improves power efficiency by optimizing a dead time.
2. Description of Related Art
Portable electronic devices such as a laptop computer, a personal digital assistant (PDA), and a smart phone are increasingly used every year. How much efficiency the portable electronic device achieves is an important factor in market competitiveness. This is because since the portable electronic device uses a battery as a voltage source, a time for use of the portable electronic device becomes longer with a higher efficiency. Therefore, research is being conducted to improve the efficiency of the portable electronic device.
In general, the portable electronic device uses a synchronous DC-DC converter. In the synchronous DC-DC converter, two switching elements are complementarily operated at a driving terminal Here, in order to reduce switching loss and stress generated in a case where the two switching elements are simultaneously in an on-state, when one switch becomes completely an off-state, the other switch should become the on-state. Accordingly, a dead time in which all of the two switches are in the off-state is caused.
Here, it is necessary to maintain the dead time to be optimal in order to enhance the power efficiency of the synchronous DC-DC converter.